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publish
function
deprecated
operator
Returns a ConnectableObservable, which is a variety of Observable that waits until its connect method is called before it begins emitting items to those Observers that have subscribed to it.
Deprecation Notes
Will be removed in v8. Use the connectable
observable, the connect
operator or the share
operator instead. See the overloads below for equivalent replacement examples of this operator's behaviors. Details: https://rxjs.dev/deprecations/multicasting
publish<T, R>(selector?: OperatorFunction<T, R>): MonoTypeOperatorFunction<T> | OperatorFunction<T, R>
Parameters
selector |
OperatorFunction<T, R> |
Optional. Default is Optional selector function which can use the multicasted source sequence as many times as needed, without causing multiple subscriptions to the source sequence. Subscribers to the given source will receive all notifications of the source from the time of the subscription on. |
Returns
MonoTypeOperatorFunction<T> | OperatorFunction<T, R>
: A function that returns a ConnectableObservable that upon connection causes the source Observable to emit items to its Observers.
Description
Makes a cold Observable hot
Examples
Make source$
hot by applying publish
operator, then merge each inner observable into a single one and subscribe
import { zip, interval, of, map, publish, merge, tap } from 'rxjs';
const source$ = zip(interval(2000), of(1, 2, 3, 4, 5, 6, 7, 8, 9))
.pipe(map(([, number]) => number));
source$
.pipe(
publish(multicasted$ =>
merge(
multicasted$.pipe(tap(x => console.log('Stream 1:', x))),
multicasted$.pipe(tap(x => console.log('Stream 2:', x))),
multicasted$.pipe(tap(x => console.log('Stream 3:', x)))
)
)
)
.subscribe();
// Results every two seconds
// Stream 1: 1
// Stream 2: 1
// Stream 3: 1
// ...
// Stream 1: 9
// Stream 2: 9
// Stream 3: 9
See Also
© 2015–2022 Google, Inc., Netflix, Inc., Microsoft Corp. and contributors.
Code licensed under an Apache-2.0 License. Documentation licensed under CC BY 4.0.
https://rxjs.dev/api/operators/publish